Occupational studies are conducted to identify and quantify chemical and other causes of cancer and to understand mechanisms of carcinogenesis. Major etiologic investigations focus on working populations exposed to benzene, other organic solvents, aromatic amines, acrylonitrile, formaldehyde, diesel exhausts, combustion products, and silica. Etiologic investigations utilize sophisticated industrial hygiene methods to assess occupational exposures and biochemical components to elucidate mechanisms of carcinogenic action and individual susceptibility. During the last year, a large study of workers exposed to acrylonitrile found that exposures at the levels studied is not associated with an increased risk for most cancers of interest. An excess of lung cancer was found in the highest exposure group, however, consistent exposure-response relationships were not identified. Potential cancer risks among commercial airline pilots and navigators were investigated. Occupational risk factors were investigated in a large case-control study of prostate cancer, showing that occupation is not a major determinant of prostate cancer. Occupations associated with metal and textile dust in Shanghai, China were associated with pancreatic cancer. Studies of occupation-related mortality in 24 states characterized race-specific cancer mortality in U.S. firefighters, showed increased peritoneal cancer in occupationally-exposed workers, evaluated risks for brain cancer in workers exposed to lead and occupational risk factors for cancer of the gastric cardia, pancreas, and prostate. Also in this series of studies, occupational physical activity was found not to be associated with non- Hodgkins lymphoma (NHL). - occupation, - Human Subjects & Human Tissues, Fluids, Cells, etc.